The objective of this proposal is two-fold. One, to provide training and skills to be able to obtain a PhD in Microbiology/Immunology and two, to study the regulation of oral immunity as induced by the peroral consumption of S. mutans and relate it to the Idiotypic Network. Rats will be orally immunized with S. mutans and taken through stages of activation followed by suppression. Serum and lymphocyte supernatants will be tested for activation or suppression on naive lymphocytes cultured in the presence of S. mutans. Activity will be measured either through ELISA techniques. Specific hybridomas will be developed to provide active suppressive factors and antibodies for use in further experiments. Standard hybridoma techniques will be followed. Rat tumor cells are available from which to construct hybridomas although T cell hybridomas have also been derived through the fusion of rat cells with a murine thymoma. Regulatory factors found will be characterized. It will be determined if suppressive activity can be absorbed by antigen. Experiments will also be done to determine if suppressor factors bind antibody (act like anti- idiotype). This will be accomplished via affinity chromatography techniques. Purifications will be accomplished through combinations of gel filtrations and column chromatography. The successful completion of this project will add new insight into the mechanisms and regulation of oral tolerance. Identification of these regulatory factors and the development of specific hybridomas will greatly enhance future study into this area of immune regulation. The ability to control these factors will enable manipulation of the immune response and possibly change the course of disease processes.